Facile Synthesis of Selenocarboxamides from Nitriles Using Se/CO/H O under Atmospheric Pressure 213
2
Data of Products
1
1
5
b: H NMR (Me
2
SO-d , 400 MHz), δ 7.38–7.89 (m,
6
13
H), 10.21 (1H), 10.80 (1H). C NMR (Me
2
SO-d ,
6
400 MHz), δ 127.40, 127.90, 131.25, 142.17, 203.89
(
C Se).
1
2b: H NMR (Me
2
SO-d , 400 MHz), δ: 7.09–7.98
6
(
m, 5H), 9.76 (1H), 10.57 (1H), 2.52 (s, 3H).
1
3
b: H NMR (Me
H), 7.75–7.78 (4H), 10.05 (1H), 10.77 (1H).
SO-d , 400 MHz), δ 20.07, 127.38, 127.55,
301.12, 1312.14, 146.02, 204.77 (C Se).
2
SO-d , 400 MHz), δ 2.31 (s,
6
SCHEME 2
1
3
3
C
NMR (Me
1
2
6
of sterically hindered selenocarboxamides such as
1
4
b: H NMR (Me
.99 (2H), 10.38 (1H), 10.99 (1H). C NMR (Me
, 400 MHz), δ 127.97, 129.18, 136.17, 140.82,
02.22 (C Se).
2
SO-d , 400 MHz), δ 7.58 (2H),
6
3b (entries 1–6). The aromatic selenocarboxamides
13
7
d
2
2
SO-
are obtained as yellow solid and are stable enough
under nitrogen at ordinary temperature. However,
when aliphatic nitriles were used as the reaction
substrates, poor yields (30%–45%) of the corre-
sponding products were obtained (entries 7–10). The
reasons are that these selenocarboxamides isolated
were thermally unstable under nitrogen and highly
sensitive to air. Aliphatic selenocarboxamides are
assumed to be less stable because of the lack of con-
jugation between the aromatic ring and the seleno-
carbonyl group observed in aromatic ones.
6
1
5
b: H NMR (Me
.66 (2H), 10.54 (1H), 11.21 (1H). C NMR (Me
, 400 MHz), δ 120.66, 149.17, 149.82, 202.08
C Se).
2
SO-d , 400 MHz), δ 7.70 (2H),
6
13
8
d
(
2
SO-
6
1
6
b: H NMR (Me
2
SO-d , 400 MHz), δ 7.40–8.19
6
(
m, 7H), 10.60 (1H), 11.28 (1H).
1
7
b: H NMR (Me
2
SO-d , 400 MHz), δ 4.14 (2H),
6
7
.08–7.76 (5H), 9.94 (NH), 10.53 (1H), 11.06 (1H).
13
C NMR (Me
11.80, 118.50, 118.91, 121.72, 124.30, 126.96,
36.13, 209.65 (C Se). Anal. Calcd for C10 10SeN :
2
SO-d
6
, 400 MHz), δ 45.82, 109.20,
In analogy with the mechanism proposed
for the reaction of aromatic aldehydes with
1
1
H
2
Se/CO/H O/DMF, the possible mechanism for the re-
2
C 50.64, H 23.70, N 11.81; found: C 50.52, H 23.68,
N 11.97.
action of nitriles with Se/CO/H
Scheme 2.
2
O/DMF is shown in
1
8
b: H NMR (Me
2
SO-d , 400 MHz), δ 4.02
6
In summary, a facile method for the syn-
thesis of selenocarboxamides from nitriles using
13
(
2H), 7.13–7.43 (5H), 7.87 (1H), 10.17 (1H).
NMR (Me SO-d , 400 MHz), δ 56.12, 128.20, 128.43,
29.52, 129.84, 135.47, 211.46 (C Se).
C
Se/CO/H O/DMF under atmospheric pressure has
2
2
6
1
1
been found. The present method for the synthesis of
selenocarboxamides described obtained high-yield
aromatic and heterocyclic selenocarboxamides with
simple and facile operations and made it possible to
prepare unstable aliphatic selenocarboxamides.
1
9
b: H NMR (Me
2
SO-d , 400 MHz), δ 0.92 (3H),
6
.73 (2H), 2.65 (2H), 9.91 (1H), 10.15 (1H).
1
1
0b: H NMR (Me
5H), 4.19 (2H), 10.28 (1H), 10.73 (1H). C NMR
Me SO-d , 400 MHz), δ 14.04, 24.59, 60.77, 166.65,
00.74 (C Se). Anal. Calcd for C SeO N: C 30.93,
2
SO-d
6
, 400 MHz), δ 1.27–1.32
13
(
(
2
2
6
5
H
9
2
EXPERIMENTAL PROCEDURE FOR THE
SYNTHESIS OF SELENOCARBOXAMIDES
H 0.46, N 11.86; found: C 31.08, H 0.42, N 12.06.
ACKNOWLEDGMENT
In a 100-mL three-necked flask, nitrile (2.5 mmol),
selenium (2.5 mmol), water (2 mL), DMF (20 mL),
and a magnetic stirring bar were placed. Carbon
monoxide was introduced and bubbled into the re-
We acknowledge the financial support from
China
Postdoctoral
Science
Foundation
(No. 20070410876).
◦
action mixture with vigorous stirring at 90 C for 5 h.
After the reaction was complete, 20 mL water was
added and the reaction mixture was extracted with
diethyl ether (3 × 40 mL). The organic phase was
REFERENCES
[
1] (a) Cohen, V. I. Synthesis 1979, 66; (b) Cohen, V. I.
J Heterocycl Chem 1979, 16, 365; (c) Mamoru, K.;
Takayuki, S.; Katsuhiro, Y.; Hideharu, I. J Chem Soc
Perkin Trans 1 1999, 453.
dried over anhydrous MgSO , filtered and evapo-
4
rated the solvent under reduced pressure to afford
a yellow oil. Further purification by column chro-
matography on silica gel or TLC gave the pure prod-
uct. All the products were identified by NMR and/or
comparison with the authentic samples.
[
2] Dell, C. P. In Comprehensive Organic Functional
Group Transformations; Moody, C. J. (Ed.); Elsevier:
Oxford, UK, 1995; Vol. 5, p. 565.
[3] Cohen, V. I. Synthesis 1978, 668.
Heteroatom Chemistry DOI 10.1002/hc